Rules of declaring variable names

Variable names can be freely named within some rules. Today, let's look at the rules for declaring variable names.

1. Variable names include only alphanumeric characters and underbar (_).

2. Variable names distinguish between upper and lower case letters.

3. Variable names distinguish between upper and lower case letters.

4. Reserved words can not be used. (Eg, if, for, while etc.)

Types of reserved words

abstract	case	continue	extends	for
import	long	private	static	throw
var	boolean	catch	default	false
function	in	native	protected	super
throw	void	break	char	do
final	goto	instanceof	new	public
switch	transient	while	byte	class
double	finally	if	int	null
return	synchronized	true	with	case
const	else	float	implements	interface
package	short	this	try

For example, the following variables are not allowed:

1hi = "hello";    wrong since it begins with a number.
if = "hello";   wrong since it uses a reserved words.
sos+dfdf = "hello";  wrong since is has +

Let's wrap up this lesson here ^^